What are the requirements for the structure and selection of vacuum furnaces
Vacuum furnace can be divided into vertical and horizontal series according to its structure, and vertical series can be divided into bell jar lifting type and bottom tray lifting type. Horizontal series is divided into single-door structure and front-back double-door structure. The furnace body adopts water-cooled wall structure.
The heating and insulation chamber is composed of two types: all-metal type and composite type, all-metal type is composed of heat-resistant stainless steel and molybdenum screen, and composite type is composed of heat-resistant stainless steel, molybdenum screen and carbon felt, mullite fiber or silicate fiber. The specific selection depends on the user's technological conditions and requirements for the technological environment.
There are several types of heaters, such as nickel-chromium wire (strip), molybdenum wire (strip, rod), graphite, etc. The specific selection depends on the maximum temperature required by users. Heaters are distributed in two ways: four-sided heating and omni-directional heating, to ensure the user's requirements for uniform temperature in the furnace.
Cooling system includes Roots blower external circulation structure, centrifugal blower external circulation structure, cold wall centrifugal blower internal circulation structure and other types to meet the requirements of different cooling rates.
Vacuum pumping system includes ion pump turbomolecular pump mechanical pump, turbomolecular pump mechanical pump, diffusion pump Roots pump mechanical pump, Roots pump mechanical pump, cryogenic condensation pump mechanical pump and other types, according to the ultimate vacuum index selection (vacuum furnace).
Temperature control adopts imported intelligent temperature controller, which can realize the automatic control function of heating, constant temperature and cooling; has the storage function of process curve, which can store many different process curves; has the function of adjustable heating and cooling speed and accurate clock, which can display the actual temperature and setting temperature at the same time; and has the function of self-calculation of PID parameters and power-off protection.
It has perfect alarm and protection measures.
It is equipped with imported multi-point recorder, which can record the vacuum, pressure, temperature and other process curves of the whole process, so as to facilitate process analysis, quality monitoring and production management.
Vacuum gauge can be selected with high reliability imported digital intelligent vacuum gauge or domestic high quality vacuum gauge, to ensure that the vacuum degree and temperature control chain, to meet the technological requirements.
The whole process control is accomplished by imported programmable logic controller (PLC). All actions are protected by chain operation. It has two working modes, manual and automatic. Users can choose either the whole manual working mode or the mode of industrial computer group control.